Question

Which of the following oxide is formed when potassium metal is burnt in excess of air ?

• A. $K_{2}O$
• B. $KO$
• C. $K_2{O}_2$
• D. $K{O}_2$

Answer 1

Answer: (A)

$K_{2}O$

Burning K in excess O2 gives the superoxide K+O2- Reaction with a large excess of metal will form the Oxide K2O. The superoxide reacts with water to form the peroxide, K2O2, at low T and the oxide at higher T both with liberation of O2.